1. Field of the Invention
The present invention relates to a stem cell, and more particularly, to an endometrial polyp stem cell.
2. Description of Related Art
The human endometrium contains substantial vascularized stroma and regenerates regularly with each menstrual cycle. Previous studies identified stem/progenitor cells residing in the human endometrium (Gargett, 2006). Regeneration initiated by cells in the basalis layer replace cells shed during menstruation. Additionally, colony-forming stem cells were identified in the human endometrium (Schwab and Gargett, 2007).
Stromal or mesenchymal stem cells (MSCs) are self-renewing cells that can differentiate into mesodermally derived tissues and have been identified in several stroma-containing tissues such as bone marrow, adipose tissue, the cord matrix, and skeletal muscle (Ding et al., 2007a). The scientific community has recognized the remarkable developmental/differentiation plasticity of MSCs (Grove et al., 2004), which have garnered considerable attention.
In a culture, MSCs are plastic-adherent, spindle-shaped cells that express a panel of surface markers, including CD105 (endoglin, SH2), CD73 (ecto-50 nucleotidase, SH3, and SH4), CD166 (ALCAM), CD29 (b1-integrin), CD44 (H-CAM), CD90 (Thy-1), and STRO-1. In contrast to hematopoietic stem cells (HSCs), MSCs are negative for CD45, CD34, and CD133 (Jones et al., 2002).
Endometrial polyps are localized hyperplastic overgrowths of endometrial glands and stroma around a vascular core that form a sessile or pedunculated projection from the endometrial surface. Endometrial polyps cause intermenstrual bleeding, irregular bleeding, and menorrhagia (Hillard, 2006).
In the present invention, stem cells have been isolated from endometrial polyps and characterized as MSCs.